前驱地震波的试验研究及波谱分析

研究了含预置裂纹的有机玻璃试样在加载实验过程中，大破裂之前出现的长周期、小振幅低频事件，并与大地震前可能出现的同类现象（即前驱地震波）进行了对比研究，根据波形记录和频谱分析得出：前驱地震波是地壳介质的长周期波动，是一种客观存在的前兆特征，具有短临前兆意义。     

前兆观测中的远场效应及其成因机制的初步探讨

在近２年的前兆观测实践中，我们发现了一种十分有趣的，奇特的现象，在１９９６年３月１９日新疆阿图什６．９级强震发生前和１９９７年３￣４月新疆伽师６级强震群发生前，在远隔２５００公里外的四川地区观测到了多种前兆手段的群体突变事件。我们称它为强震的“远场效应”。本文还对它的成因机制作了初步的探讨。     

主键约束在数字化前兆数据服务软件中的关键运用

数字化前兆数据库是一个分布式网络数据库SQLServer,数据库的建成运用为预报人员的日常数据分析提供了一个准确的、完整的资源平台。为考虑数据库设计完整性规则 ,本文着重讲述建立两套前兆数据库的过程中 ,主键约束在数字化前兆数据服务软件EPDS的建库及入库中起的重要作用。     

真三轴单面临空下煤岩组合体冲击破坏特征试验研究

煤岩复合承载结构所处的应力边界条件不同,冲击地压在巷道中的显现特征和前兆规律亦不相同。采用高频振动采集及孔内成像三轴动静载试验系统,开展了高静载和动静载耦合作用下煤岩组合体真三轴单面临空试验,分析了煤岩组合体界面处力学特征和强度条件,探究了不同应力边界下煤岩组合体的破坏形态、动力显现特征和声发射信号的演变规律。研究结果表明:(1)受煤岩变形相互制约的影响,交界面处砂岩强度被"弱化"。当界面处煤体裂隙尖端的应力大于"弱化"后砂岩强度时,裂隙将穿过煤岩界面发育至砂岩中,砂岩呈现出屈曲层裂、劈裂成板的破坏形态。(2)高静载作用下,煤岩组合体变形破坏特征和声发射信号具有明显的前兆规律,组合体发生承载失效前煤体局部颗粒弹射动能增大、弹射颗粒块度降低,声发射信号由"高频低能"向"高频高能"转变,组合体的破坏形态以剪切-张拉复合破坏为主。(3)受冲击动载影响,顶底板砂岩夹持作用减弱,煤体裂纹尖端应力得不到有效积聚,裂纹扩展到煤岩交界面时被阻隔,组合体以煤样的张拉破坏为主,声发射信号呈现出"高频高能"的特点,但大多集中在冲击破坏之后,导致组合体动力破坏难以预测。(4)与纯静载作用相比,虽然动静载耦合作...     

用同相叠加方法识别定点形变数据中的降雨影响

分别以昆明台、云龙台为例,用数据同相位叠加的方法分别对形变数据中的典型图像及其对应时段的降雨数据进行叠加,以判断典型图像是否与降雨有关。结果表明,昆明台形变观测中多次出现的同步转折为降雨影响;而云龙台的转折现象则与降雨无关,其来源及属性需要进一步研究。     

Quantitative study on characteristic parameters of acoustic behavior habits in budgerigars ( Melopsittacus undula fus )

On the bases of the studies of acoustic behavior and pattern recognition of budgerigar calls, the quantitative study on characteristic parameters of acoustic behavior habits in budgerigars is further given in this paper. These results open up a new knowledge for comprehensive analyses of abnormalities of acoustic behavior habits in budgerigars prior to earthquakes. Under indoor lighting, the song calls in budgerigars are possessed of the beginning and ending singing time with the natural characteristics, and of the rhythmic habit of daylight singings and night rests. In daily daylight and night calls, single calls, vari-toned calls, mono-syllabic and multi-syllabic protest calls are respectively possessed of the occupation habit corresponding to behavior activities, and have close acrophases and regular following properties corresponding to half-value phases, and the acrophases delay half-value phases by about half an hour on an average. After reversing lighting, the acrophases of budgerigar calls delay those of the normal lighting by about 12 hours on an average, and the following properties corresponding to half-value phases are irregular. This subject is supported by the Chinese Joint Seismological Science Foundation.     

Quantitative study on characteristic parameters of acoustic behavior habits in budgerigars （Melopsittacus undulafus）

Ｑｕａｎｔｉｔａｔｉｖｅｓｔｕｄｙｏｎｃｈａｒａｃｔｅｒｉｓｔｉｃｐａｒａｍｅｔｅｒｓｏｆａｃｏｕｓｔｉｃｂｅｈａｖｉｏｒｈａｂｉｔｓｉｎｂｕｄｇｅｒｉｇａｒｓ（Ｍｅｌｏｐｓｉｔｔａｃｕｓｕｎｄｕｌａｆｕｓ）Ｊｉｎ－ＣｈａｎｇＪＩＡＮＧ（蒋锦昌）；Ｈ...     

A sequence of seismic activity in the Kanto area precursory to the 1923 Kanto earthquake

The Kanto earthquake (M=7.9) that occurred along the Sagami Trough in the Sagami Bay on 1 September 1923 was one of the most disastrous earthquakes in Japanese history. The Kanto area includes Metropolitan Tokyo and Yokohama which are densely populated, and hence it has been a matter of great concern, from the viewpoints of earthquake prediction and disaster prevention, whether or not the 1923 Kanto earthquake was preceded by precursory seismicity. A study using the most complete lists of earthquakes catalogued recently by Utsu and the Japan Meteorological Agency reveals that seismic activity in the Kanto area was appreciably higher before and after the Kanto earthquake, and that the Kanto earthquake was preceded by a sequence of anomalous seismic activity, quiescence, and foreshocks. Such higher activity before and after the Kanto earthquake is contrasted with low seismicity during the recent 30-year period. A model is proposed to explain the precursory seismic activity, subsequent quiescence, and foreshocks for the Kanto earthquake. In the model, the transition from precursory seismic activity to quiescence is ascribed to time-dependent fracture due to stress-aided corrosion. Foreshocks are related to an acceleration of premonitory slip shortly before the mainshock slip.     

1998年宁蒗6.2级系列地震的短临前兆异常特征

与以往的震例相对相对比,１９９８年宁蒗６．２级地震的短临前兆异常,既有异常幅度大,空间分布上受活动性断裂带控制,时间进程上是准同步起伏,前兆异常与震兆异常配套出现,策观异常与宏观异常配套出现等共性;又有前兆异常十分丰富,异常的空间分布集中,震后效庆十分平衡等个性。     

“短期气候预测专刊”

A premonitory sign of an anomalous SST over the eastern equatorial Pacific shows up in the North Pacific Subtropical Mode Water (STMW) 18 months earlier,and the air-sea relationship between the STMW and the anomalous SST over the eastern equatorial Pacific is shown.This premonitory connection involves an air-sea coupling between the longtime persistent mid-latitude sea surface temperature anomaly (SSTA) induced by the remote re-emergence of the STMW and the following spring subtropical atmospheric circulation anomalies.An examination of the air-sea interaction reveals that the following spring subtropical atmospheric circulation,which responds to the longtime persistent SSTA,is dominated by the anomalous negative (positive) geopotential height downstream of the negative (positive) SSTA in the strong (weak) STMW case.Thus,the tropics adjust to these anomalies through coupled dynamics,producing positive (negative) SST anomalies over the eastern equatorial Pacific.A cold water event that occurred over the eastern equatorial Pacific during winter 2008-09 was successfully forecasted by the weak summer STMW index in 2007.The evolution of this process for the air-sea interactions from the autumn of 2007 to December 2008 is presented.